Copper anode furnaces, in which copper melt is refined into anode copper by means of fire refining and then the copper is poured out in anode form, are known. The anodes are further processed by means of electrolysis. The quality of the anodes substantially affects the power consumption, i.e. the cost-effectiveness of the electrolysis.
The copper anode furnace is known to comprise a furnace drum which can be pivoted about a horizontal axis and in which the copper melt with 95-98% copper is brought in two stages to a purity level of approximately 99%, oxidation of the undesired accompanying elements (primarily the sulphur) taking place first of all, and then the oxygen content which has risen significantly due to the oxidation is reduced again in a reduction phase. The copper is poured out via a run-off hole disposed on the periphery of the furnace drum. When pouring out the furnace drum is turned bit by bit in order to regulate the casting speed and to take account of the falling molten bath level. A number of disadvantages arise from this. Due to the position of the run-off hole—very close to the surface of the bath—slag is also poured off, and this has a negative impact upon the anode quality. In addition, the fall height of the copper from the run-off into a channel system is very high, and so the oxygen which one had taken pains to remove is taken up again, and this also leads to worsening of the anode quality. Moreover, the environment is seriously contaminated by the sprayed copper, material losses also being observed.